Electrical switch



April 10, 1945. H. GOODMAN ETAL ELECTRICAL SWITCH 2 Sheets-Sheet 2 FiledJune 25, 1943 Fig 4 Patented Apr. 10, 1945 ELECTRICAL SWITCH HarryGoodman, Britton, and Ralph M. Wolfe,

Oklahoma City, Okla.

. Application June 23, 1943, Serial No. 492,172

7 Claims.

Our invention relates to electrical switches, and

more particularly to switches in which an electrically conductive liquidis used for making and breaking an electrical circuit.

One object of the invention is to provide a liquid switch in which anelectrical circuit will be completed or broken only after the expirationof a desired time from the moment at which the switch is actuated, inother words, a delayed action switch.

In some electrical systems it is desirable to close one electricalcircuit, and then, after the lapse of a limited time, to have anothercircuit automatically become completed. In such systems it is usuallydesirable to have the two circuits open or break in reverse order tothat in which they wer closed. For instance, in an electrically poweredhumidifier system, it is necessary that the circuit to the motor for'driving a fan be first closed, and then after the motor has had time toreach its operating velocity, the moin order to prevent flooding.

Consequently it is an important object of the invention to provide aliquid switch which will function to close two electrical circuits intimed relation, and which will function to break the circuits in reverseorder to that in which they were closed, but also in timed relation toeach other.

The present switch is designed to be operated to opened and closedpositions by an electro-magnet or solenoid. Since most liquid switchesuse mercury as-a contact making agent, and since mercury is extremelyheavy, damage to the switch couldwell occur if the switch was to bethrown instantaneously by such magnetic apparatus.

It is therefore another object of the invention to provide a switch forthe above described purpose, but in which has been incorporated a slowmotion feature to prevent damage to the valve while in open, or circuitbreaking position Figure 2 is a similar view of the switch while incircuit closing position;

Figure 3 is an elevational sectional view looking in the direction ofthe arrows from a point indicated by the line 3-3 of Fig. 1;

Figure 4 is a view similar to that of Fig. 3, but looking from the line4-4 of Fig. 2;

Figure 5 is a fragmentary top view detailing the clamp bracket or clipfor removably holding the liquid containers;

Figure 6 is a side elevational view detailing a gear used as a part ofthe switch;

Figure 7 is an end elevational view of the same gear; and,

Figure 8 is a vertical sectional view through a liquid container andvalve which may be used in lieu of those-detailed in Figs. 1 and 2.

Like characters of reference designate like parts in all the figures.

In the drawings:

The reference numeral l indicates as a whole a mounting element orsupport for the switch. In the present instance the support I has beenillustrated in the form of a wall bracket having a flat base 2 adaptedto be attached to a wall 3 by screws or bolts inserted through suitableholes 4. The support or bracket 1 further includes two spaced standards5 projecting perpendicularly from the base 2 and preferably being madeintegral therewith. The free end of each of the standards 5 carries aconventional bearing 6, and the two bearings 6 journal for rotation ashaft 7!. The shaft 1 extends in both directions for some distancebeyond the bearings 6, and its free ends are each equipped with a springclip 8 (Fig. 5) for removably retaining a liquid container. The liquidcontainers will be described in detail hereinbelow.

Intermediate the two bearings 6, the shaft 1 is provided with a toothedgear 9 which is freely and independently rotatable upon the shaft. Oneend face of the gear 9 is provided with a lug or boss l0 having anabrupt face H. The gear 9 is kept from longitudinal movement along theshaft by any suitable or conventional means, not shown, but which may bea reduced diameter groove in the shaft or could be set-collars. In therotative path of the lug ID, the shaft 1 is provided with a rigidoutstanding lug or projection [2 adapted to be engaged by the face I Iwhen the gear is partially rotated upon the shaft as and for a purposewhich is more fully described hereinbelow.

The shaft 1, between th bearings 6 is further by-pass.

provided rigidly with an outwardly projecting weight l3.

The apparatus thus far described constitutes the mounting and actuatingmechanism for two occluse liquid containers which are designatedrespectively by the reference characters A and B, and which will now bedescribed.

The container A consists .of a hermetically sealed or closed hollow bodyhaving an interior septum or partition 2| with a comparatively largecentral through bore or port 22, and a minute through bore 23, whichmight wellbe termed a A ball valve 24 is provided adjacent one end ofthe central bore 22, and when the body 26 is in the position illustratedin Fig. 1, the ball 2a is adapted to gravitate into a position toclosethe bore 22. 'A suitable stop or cage 25 is provided for the purpose oflimiting movement ofthe ball 24 away from the partition 2i. The endportion 50 of the body 20, or thatend which containsthe ball 24, has'twoelectrodes 26 and 21 piercing and hermetically sealed into thewall ofthe body, and lying in identical planes. Electric conductors 28 and 29connect respectively the electrodes at points lying outside of the body20. An electrical conductive liquid 30, such as mercury, is providedwithin the container A.

It may be readily understood that should'the container A be inverted,the ball 24 would drop away from the position in which it closes theorifice 22, and the liquid 30 would then gravitate into and sufiicientlyfill the end portion to form an electrical contact between the terminals26 and 27. In Fig. 2 the container A is shown after it has been invertedfrom the original position as shown in Fig. l. a l

The container B is identical with the container A except that thepartition 2i has been inverted and the ball 34 is below the partition,or in other words is in the'end portion 5| when the container i is inthe position shown in Fig. 1. In other words, when the ball 24 of thecontainer A-is in the closing position, the ball 34 of the container Bis in its opening position.

Should the container B be'inverted from its position as shown in Fig. 1,soas to bringthe end portion '5! uppermost, the ball 34 therein wouldthenseat and close the central orifice or port 22 in the partition.Seating of the ball 34 would prevent gravitation of the liquid below thepartition, except by passage through the minute perforation orby-pass235 By the sametoken, if the container was again inverted afterthe liquid had flowed out at the end portion 5| of the container B, theball 34 would fall away from the partition and allow the liquid 30toimmediately pass through the central bore 22 back into the end portion5! of the container.

The container B has two or moreterminals 36 and Si which may be bridgedby the liquid 30 therein when the container is in theposition shown inFig. 2. It is pointed out that terminals 26 and 21 and the terminals 36and'3'l are located in similar ends of the containers A and Brespectively. In installing the device in, the system,

the terminals 26 and 21 are made a part of one electrical circuit whileterminals 36 and 3'! are made a part of a different circuit.

For the purpose of explaining the operation of the device, andillustrating the function of the above described switch in two circuitsof an electrical system, we will assume that the installation is made ina humidifying system. The system will consist of three circuitsdescribed as follows:

1. A circuit in which a humidostat and the solenoid IS are wired inseries, the humidostat being adapted to close the circuit in order toenergize the solenoid when humidity in the place at which it is locatedbecomes too low, and to open the circuit and de-energize the solenoidwhen the humidity reaches a desired high point;

2. A fan or blower circuit including a motor driven fan, with oppositesides of the circuit being connected to the terminals 26 and 21, thewir-' ing arrangement being such that the motor will be energized whenthe terminals 26 and 27 are The word humidostat, as used herein, refersto any instrument capable of automatically determining humidity or beinginfluenced accurately by change in humidity in the room or place whereit is located. V

With the above three circuit system in mind, and with the switchmechanism in the position as shown in Fig. -1, there will be noelectrical connection between the terminals 26 and 21 or between theterminals 36 and 31'. The solenoid core I5 is at the lower end of itsthrow, indicating that the solenoid I6 is not energized. Therefore nocircuit of the system is closed.

Should the humidity become such that the humidostat closes the,solenoid. circuit, the

core 15 of the solenoid will instantly'be pulled upwardly. This upwardmovement will rotate the gear 9, causing the abrupt face H'of the bossor lug ID to be moved from contact with the projection' [2 on theshaft 1. Such movement of the lug ill will release the shaft 1 to apartial rotation under the influence of the weight l3, which will swingfrom its upright position as shown in Figs. 1 and 3, to a dependingosition as it is shown in Figs. 2 and 4. The weight 13 issufiicient toove'rbalance the liquid 30 in'the bottom ends of the two containers Aand B. The containers A and B are therefore inverted to bring the liquid30 into the new upper ends of the containers.

At thi instant of the operation; the ball 24 will be below the partition2| and will fall away from the center bore or port 22,therethrough,permitting the liquid 30 to immediately: flow into the lower end 50 ofthe container A and reach a level therein sufiiciently high to bridgethe terminals 26 and 21,- and thus close the second circuit of thesystem, i. e., the fan driving or blower circuit.- This will start thefan motor.

the liquid 30 thereabove, will cause the ball 84 to seat and close thecentral bore through the partition. The liquid can therefore reach thelower end of the partition only by passing through the minuteperforation or by-pass 23 therein. The minute perforation 23 in thepartition 2| of the container B is of such a size, that a desired timemust elapse before all of the liquid 30 in the container B will passfrom the upper end 5| to the lower end of the container B in order tobuild up to a sufiicient level to electrically connect the terminals 36and 31 and thereby close the third circuit of the system, i; e., theatomizer circuit. In the container B as shown in Fig. 2, this time haselapsed and the third circuit has been closed. The system is thereforein full operation.

As stated hereinabove, the original partial rotation of the gear 9causes the lug II! to be moved away from the projection or lug 12 on theshaft 8, but when the shaft then rotates under the impetus of the weightI 3, this projection again come the combined weight of the liquid in vthe two containers and that of the weight 13, and consequently the shaft8 will be rotated to the original position, or that position which itoriginally assumed in Figs. 1 and 3.

This last described rotation of the shaft 8 is accomplished by action ofthe rack teeth 14 to rotate the gear 9, and rotation of the gear 9 urgesthe face H of the lug Ill against the projection 12 of the shaft 8. Thecontainers A and B are consequently returned to the positions shown inFigs. 1 and 3. At this instant of the operation the liquid 30 willreside in the upper ends of the containers.

When the containers have thus been inverted from their positions of Fig.2, the ball 34 in the container B will immediately fall away from thecentral bore of the partition 21 therein, and the liquid 30 in thecontainer B will immediately flow into the then lower end 5! of thecontainer B, thus breaking the electrical connection between theterminals 35 and 31. The atomizer circuit will thus be broken.

At the same instant of the operation, the ball 24 in the end portion Ellof the container A will seat over and close the central port 22 of itspartition. The liquid 30 in the container A will thus be retained in theupper end thereof for the time it takes it to pass through the minutepassage 23. The electrical connection between the terminals 26 and 21will therefore not be broken until some time after the atomizer circuithas been broken.

From the above description it will be apparent that a liquid switchmechanism has been provided which, when originally operated willimmediately close the second circuit of the electrical system, and whichwill then, after a time lapse,

close the third circuit of the system. Also, that when again operated,the switch mechanism will first function to break the third circuit ofthe system, and after an elapse of time will automatically break thesecond circuit of the electrical system.

. the container.

In most liquid switches the liquid used is mercury. Since mercury is acomparatively heavy material, and since solenoids act substantiallysimultaneously, the present switch operating mechanism has been arrangedto be moved in both directions by gravity. This has been done in orderto prevent damage to the containers, which damage might well occur if adirect connection were made between the shaft 8 and the solenoid 16.

Since, as stated above, mercury is a comparatively heavy liquid, theballs 24 and 34 must be made of some material heavier than mercury, suchas gold, platinum, or the like. This fact renders the switch of Figs. 1to 7 quite expensive, although not prohibitively so. For this reason aslightly different embodiment of the valve construction has beenprovided as an alternative. Thi embodiment is illustrated in Fig. 8 ofthe drawings.

In this embodiment a container C has its upper and lower ends separatedby a partition 40 having a minute through perforation or by-pass 41similar in oillce to the passage 23 of Figs. 1 and 2. Instead of thecentral bore 22 of partition 21, the partition 40 has a pipe 42 passingtherethrough. The upper end of the pipe has a reverse end 43 terminatingin a downwardly facing open end 44. The ball 45 i confined in a suitablecage 46 beneath and in vertical alignment with the open end 44 of thepipe 42. The ball 45 is made of some material which is lighter than theliquid 41 in the container 40.

In this embodiment, if the container C were to be inverted from theillustrated position, the liquid 41 would pass downwardly through thepipe 42, would float the ball 45 away from the open end 44 of the pipe42, and would freely enter the then lower end of the container withoutobstruction.

If the container C were to be again inverted, or moved back to theposition shown in Fig. 8, the liquid 41 would then reside in the upperend of The ball 45 would now float upwardly and close the open end 44 ofthe pipe 42, and would "remain in its closing position until such timeas the liquid 41 could escape through the minute perforation 4 I.

The valve of Fig. 8 would reach the same result as that of Figs. 1 and2, so far as operation of the device is concerned, but would make itpossible to use a ball of lighter material than that of the liquid usedin the containers.

It is anticipated that liquids other than mercury may well be used inthe containers. It is also apparent that the valve structure need not beof the ball-type, but could well be constructed alon the 'lines of any.conventional check-valve.

While experiments have shown that the electrically conductive material39 i preferably of liquid, it might well develop that some otherflowable material could successively be used, for instance, it isprobable that some powdered electrically conductive material would provepractical.

We claim:

1. In an electric liquid type switch: two closed containers; a partitionin each container dividing the same into an upper and a lowercompartment; a large and a small port through each partition; a gravityactuated check valve in each container for closing one end of the largepartition port therein. said valves closable in opposite directions; aplurality of electrical terminals in the similar compartments of eachcontainer; and an electrically conductive liquid partially filling eachcontainer.

2. Inan electric liquid-type switch: two closed containers; a partitionin each container dividing the same into an upper and a lowercompartment; a large and a small port through each partition; a gravityactuated check valve in each container for closing one end of the largepartition port therein, said valves closable in opposite directions; aplurality of electrical terminals in the similar compartments of eachcontainer; and electrically conductive liquid partially filling eachcontainer; and means for selectively moving the containers to partialrotation upon substantially horizontal axes. s

3. In an electric liquid-type switch: two closed containers; a partitionin each container dividing the same into an upper and a lowercompartment; a large and a small port through each partition; a gravityactuated check valve in each container for closing one end of the largepartition mrt therein, said valves closable in opposite directions; aplurality of electrical terminals in the similar compartments of eachcontainer; an electrically conductive liquid partially filling achcontainer; and means for simultaneously moving the containers to partialrotation upon substantially horizontal axes.

4. In an electric liquid-type switch: two elongated closed containers;means for mounting the containers for simultaneous end over endrotation;a plurality of electrical terminals insimilar ends of each container; apartition in each container separating the end portions thereof, saidpartitions having a comparatively large port and a-small passagetherethrough; a gravity actuated check-valve in one container forclosing and open ing one end of the port in its partition; a checkvalvein the other container for closing and opening the opposite end of thepartition port; and an electrically conductive liquid partially fillineach container.

5. Organization as described in claim 4, in which the mounting meansincludes: a horizontally journaled shaft; and a spring clip bracket ateach end of the shaft for removably retaining a container.

6. A delayed action liquid switch for electrical apparatus including:two elongated containers for an electrically conductive liquid, bothmounted for partial simultaneous end over end rotation upon a commonaxis; a plurality of electrical conductors in the similar ends of eachcontainer; a

ported partition intermediate the ends of each,

container; a gravity actuated check-valve for the port of eachpartition, said valves closable in opposite directions; a Icy-pass forliquid in each.

